The present invention relates to surgical retractors and devices for stabilizing a predetermined area of the body during a surgical procedure, more particularly to surgical retractors and stabilizing devices used in connection with an improved segmented arm assembly that is preferably used in coronary artery bypass grafting surgical procedures, and more specifically to a segmented arm that is used with various surgical retractors and stabilization devices for use in various surgical procedures.
Diseases of the cardiovascular system affect millions of people each year and are a cause of death for large numbers of people in the United States and throughout the world. A particularly prevalent form of cardiovascular disease involves a reduction in the blood supply to the heart caused by atherosclerosis (coronary artery disease) or other conditions that create a restriction in blood flow at a critical point in the cardiovascular system affecting blood flow to the heart.
One technique for treating such a blockage or restriction is a surgical procedure known as a coronary artery bypass graft procedure, which is more commonly known as xe2x80x9ca heart bypassxe2x80x9d operation. The surgical correction of occluded or stenosed coronary arteries by means of bypass grafting are probably still the most common procedures performed today, especially when multiple grafts are needed.
In the coronary artery bypass graft procedure, the surgeon either removes a portion of a vein from another part of the body for grafting or detaches one end of an artery and connects that end past the obstruction in the coronary artery while leaving the other end attached to the arterial supply. When using a vein from another part of the body, the surgeon installs this portion at points that bypass the obstruction. In both cases, the objective is to restore normal blood flow to the heart.
In addition, when using this technique the surgeon makes a long incision down the middle of the chest, saws through the sternum, spreads the two halves of the sternum apart and then performs several procedures necessary to connect the surgical patient to a cardiopulmonary bypass machine to continue the circulation of oxygenated blood to the rest of the body while the heart is stopped and the graft is being sewn in place. Although such a procedure is one common technique for treatment, the procedure is lengthy, traumatic, considerably more expensive and can damage the heart, the central nervous system and the blood supply.
Interventional techniques, such as percutaneous transluminal angioplasty (PTCA) have gained popularity as the method of choice for therapy of atherosclerosis occlusions for several reasons. The transluminal approach is a minimally invasive technique that subjects the patient to less trauma and less recovery time, especially when compared to bypass grafts which utilize homologous tissue, such as saphenous vein grafts. Also, the patient often suffers complications at the donor site of the graft that may be worse than the sternotomy and anastomosis.
Although PTCA procedures are often successful, complications such as restenosis or thrombosis and embolism can occur. Restenosed vessels may often require surgical intervention for correction. The surgical correction of restenosis like the conventional coronary bypass surgical procedure requires the heart to be stopped and the patient placed on a heart/lung bypass machine during the procedure.
In recent years, and in an effort to reduce expense, risk and trauma to the patient, physicians have turned to minimally or less invasive surgical approaches to the heart, such as intercostal and endoscopic access to the surgical site. With such procedures, the heart is beating during the surgical procedure. Thus, there is no need for any form of cardiopulmonary bypass and there is no need to perform the extensive surgical procedures necessary to connect the patient to such a bypass machine.
Such attempts at performing minimally invasive bypass grafting on a beating heart, however, have been thought of as being tedious, dangerous and difficult because of the delicate nature of the surgical procedure, the lack of adequate access through a reduced surgical field, and the lack of a way to adequately stabilize and reduce tissue movement at the graft site. Because these procedures are performed while the heart muscle is continuing to beat, the blood continues to flow and the heart continues to move in three dimensional movement while the surgeon is attempting to sew the graft in place. Also, the surgical procedure to install the graft requires placing a series of sutures through an extremely small vessel and onto tissue that continues to move during the procedure. It is necessary that these sutures be fully and securely placed so the graft is firmly in position and does not leak.
There is disclosed in U.S. Pat. No. 5,730,757, an access platform for the dissection of an internal mammary artery. The described access platform has first and second blades interconnected to a spreader member that laterally drives the blades apart or together and support pads interconnected to the first blade. A torsional member is operably interconnected to the first blade and the spreader member and is used to vertically displace the first blade in either direction. Thus, increasing the surgeon""s working space and visual access for the dissection of the internal mammary artery. A tissue retractor interconnected to the blades is used to draw the soft tissue around the incision away from the surgeon""s work area. It is further provided that the access platform can include a port that can be used to mount a heart stabilizer instrument.
There also is described in U.S. Pat. No. 5,875,782 granted to Ferrari et al.; U.S. Pat. No. 6,033,362 granted to Cohn; U.S. Pat. No. 6,102,854 granted to Cartier et al.; U.S. Pat. No. 5,947,896 granted to Sherts et al.; and U.S. Pat. No. 5,894,843 granted to Benetti et al. various devices for stabilizing the predetermined area on a heart or other organ of a patient to enable a surgical procedure on a beating heart. These devices include various stabilization members and an elongated arm. The arm segments can be movably attached to a rib retractor so that a person is not required to hold the arm segment. In one disclosed embodiment, the apparatus further includes a device to hold a bifurcated member in a position against the surface of the heart sufficiently so that a stabilizing force is applied against the heart and contraction of the heart does not cause either vertical or horizontal motion at the target site during the surgical procedure.
There also is described in U.S. Pat. No. 5,836,311 granted to Borst et al. an apparatus for stabilizing the predetermined area on a heart or other organ of a patient to enable a surgical procedure on a beating heart. The apparatus includes a single legged or bifurcated member having a plurality of suction members thereon which are attached to the surface of the heart using suction pressure. The arm portion of this device can be movably attached to a rib retractor or other surgical device so a person is not required to hold the arm segment and the suction device may be locked into position against the surface of the heart.
It is therefore desirable to provide a new system and devices related thereto for stabilizing a predetermined area of the body, such as the heart and methods related thereto. It is particularly desirable to provide such a system and devices thereto that are less complex and more user friendly in comparison to prior art devices. Such systems and devices thereto preferably are simple in construction and less costly than prior art devices.
The present invention features a system for retracting, stabilizing or manipulating a predetermined area of a body. The system includes a sled assembly for use with a surgical retractor, a stabilization arm system or apparatus and a tissue support or stabilization device, and methods of use related thereto. Also featured is a system that supports any of a number of surgical implements, for example a diaphragm retractor, a valve retractor, a light source or suction device for use during a surgical procedure.
The stabilization system and related devices and apparatuses thereto that are featured herein are particularly advantageous for use in performing off-pump coronary artery bypass grafting procedures in which the heart remains beating during the surgical procedure and/or valve surgery where the heart is stopped. One advantage of the present invention relates to the versatile use of a segmented arm system which is connected to an arm or rack section of the retractor and also retains a stabilization device or surgical implement in a desired position. The use of the external rail system on the retractor allows the stabilization arm system to be attached to the retractor at any desired location and does not require that the stabilization arm system be slid on from an end of an arm or specially attached in certain specific locations. Additionally, the segmented arm assembly of the present invention allows for a full range of three dimensional motion of the stabilization device or surgical instrument which is controlled by a single knob that is spaced apart from each of the retractor and stabilization device. The segmented arm assembly is also easily and conveniently manipulated by the surgeon and is movable so as not to obstruct the surgeon""s view of the desired target location.
In a general aspect, the stabilization system of the present invention is preferably used for stabilizing a predetermined area the heart tissue of a patient. This system preferably includes a retractor, a stabilization device for locally stabilizing the predetermined area and/or a surgical instrument as well as a stabilization arm system that functionally secures the stabilization device to the retractor. The retractor preferably includes a rail system having two arms and a rack segment. The rack segment interconnects the two arms, for selectively spacing the two arms from each other and for maintaining the two arms in a desired fixed relationship. In a preferred form of the present invention, the two arms and rack segment are configured to receive the sled member of the stabilization arm system at the desired location thereon.
The stabilization device preferably includes devices of the type commonly known as the Cohn Cardiac Stabilizer or the Immobilizer marketed by the Genzyme Corporation of Cambridge, Mass., although horseshoe or suction type devices may also be used. The preferred form of the stabilization device is a generally square, rectangular or teardrop shaped member having a planar surface with centrally located opening therein. This opening is the area through which the surgeon performs the anastomosis or other procedure on the tissue of the beating heart. The stabilization device is preferably a multiple piece member so that once the anastomosis is completed, the pieces or an end portion thereof may be separated to remove the device from around the anastomosis. As described more fully below, flexible tapes are preferably sutured through the tissue and then threaded through the stabilizing device to provide temporary vessel occlusion. Once the stabilization device is positioned in the desired orientation and location in contact with the tissue, the flexible tapes are then pulled snug through the opening of the stabilization device to provide a system that captures the predetermined area of the tissue.
The stabilization arm system preferably includes an elongated arm having a proximal connector for attachment to the retractor and a distal connector thereon for releasably connecting the stabilization device or surgical instrument to the elongated arm. The distal connector allows the stabilization device to be pivotally and slidably moved to a desired position into contact with the predetermined area of the tissue of the patient. The stabilization arm system of this embodiment also preferably includes a pivotal segment located approximately midway along the length of the arm. The pivotal segment provides an additional location for relative movement of the stabilization device as well as providing a common location for fixing the desired position of the stabilization arm system along the retractor and relative to the stabilization device. Additionally, the pivotal segment allows the user to position at least a portion of the arm segment away from the desired surgical site so that the arm system does not obstruct the view of the surgeon or the assistant while providing sufficient leverage to provide a stable surgical site and to allow access to various locations on the heart of the patient. The stabilization arm system further includes the sled member connected to the proximal connector for removably securing the stabilization arm system to at least one of the rails on the retractor arms and/or the rack segment of the retractor and which is preferably slidable along the retractor. The stabilization arm system preferably includes a pivotal mounting mechanism which selectively engages the sled member. In the preferred form of this invention, the pivoting movement of the sled member relative to the arm is controlled by operation of the pivoting segment.
According to one aspect of the present invention, the arms of the retractor are preferably configured with a front edge and a step in the top surface thereof to form an elongated rail surface along substantially the entire length thereof. The step is preferably spaced apart a predetermined and consistent distance from the front edge and is also located on the interconnecting or rack segment of the retractor. Also, the sled assembly is preferably configured to removably engage the front edge and the step at any desired location on one or more of the arms or the rack segment of the retractor. The sled member preferably includes a lever for selectively engaging the step and front edge on the arm or rack segment of the retractor so the sled member is removably and slidably secured to the arms or the rack segment.
Other aspects and embodiments of the invention are more fully discussed below.